Lectures 3-6 Cardiac Physiology

Question 1 of 34

1

Which of the following statements are TRUE regarding cardiac myocytes?

Select one of the following:

the vast majority of intracellular proteins are fixed and carry a positive charge
The equilibrium membrane potential for Na+ is higher than the potential for K+
Action potentials are initiated by the opening of voltage gated Calcium channels
The delayed opening of voltage gated sodium channels are responsible for maintaining the plateau of the action potential
This graph is an accurate representation of the predicted membrane potential over time.

Explanation

Question 2 of 34

2

Select from the dropdown lists to complete the text.

The Na+/K+ ATPase helps maintain the resting membrane potential of roughly -85mV in cardiac myocytes.

For each unit of ATP expended ( 3, 2, 1 ) ( Na+, K+ ) Ions are pumped out and ( 2, 1, 3 ) ( K+, Na+ ) ions pumped in

Explanation

Question 3 of 34

3

During Diastole which of the following movement of ions are occurring in cardiac myocytes.

Select one or more of the following:

There is a Net Passive movement of Na+ ions into the cell
There is a Net Passive movement of Na+ ions out of the cell
There is a Net Passive movement of K+ ions into the cell
There is a Net Passive movement of K+ ions out of the cell
There is a Net Passive movement of Ca2+ ions into the cell
There is a Net Passive movement of Ca2+ ions out of the cell
Na+ is being actively pumped into the cell in exchange for K+ which is being pumped out
Na+ is being actively pumped into the cell in exchange for Ca2+ which is being pumped out
K+ is being actively pumped into the cell in exchange for Na+ which is being pumped out
Ca2+ is being actively pumped into the cell in exchange for Na+ which is being pumped out

Explanation

Question 4 of 34

3

Which of the following statements are correct?

Select one or more of the following:

At Point 1 there is a large movement of Na+ ions into the Cell
At Point 1 Voltage Gated Sodium channels are Open
At Point 1 Voltage Gated Potassium channels are Open
At Point 2 Voltage Gated Potassium channels are Open
At Point 2 Voltage Gated Sodium channels are Open
At Point 2 the dip in membrane potential is due to efflux of Ca2+ through voltage gated channels
Point 3 represents the plateau, which is maintained by Calcium efflux
Point 3 represents the plateau, which is maintained by Calcium influx
During Stage 4 passive movement of K+ though only leak channels returns the membrane potential to rest
During Stage 4 the net movement of chloride is from the ICF to the ECF

Explanation

Question 5 of 34

1

Which of the following statements is FALSE regarding the refractory period of a cardiac myocyte Action Potential?

Select one of the following:

The Absolute refractory period is due to the rapid inactivation of Na+ channels after they open, these channels are not reactivated until membrane potential is below 65mV
Due to the extended refractory period, cardiac muscle can not be tetanized
Another Action Potential can not be initiated during any of the stages 1-4
The inactivation of VO Na+ channels causes a change in the shape of the protein channel, blocking the passage of Na+ ions.
All of the above are true

Explanation

Question 6 of 34

1

Fast response action potentials occur in the SA Node

Select one of the following:

True
False

Explanation

Question 7 of 34

2

Fill the blank spaces to complete the text.

Order the following from those most permeable to sodium and calcium, to those least permeable to sodium and calcium.

1.
2.
3.
4.

Options:
Bundle of His
SA Node
Purkinje Fibres
AV Node

Explanation

Question 8 of 34

3

Which of the following are true of pacemaker cells in the AV Node

Select one or more of the following:

Resting Membrane potential is stable
Resting Membrane potential is unstable
Voltage Gated Sodium Channels are present
Voltage Gated Calcium Channels are present
Threshold is higher compared to Cardiac Myocytes
Threshold is lower compared to Cardiac Myocytes
Amplitude of the Action Potential is higher compared to Cardiac Myocytes
Amplitude of the Action Potential is lower compared to Cardiac Myocytes
Sodium Influx into the cell does not occur at any point in time
There is a greater permeability to Calcium than the SA Node

Explanation

Question 9 of 34

3

Parasympathetic/Vagal Innervation of the SA Node will result in

Select one or more of the following:

Increased Heart Rate
Decreased Heart Rate
Increased Permeability to Calcium
Increased Permeability to Sodium
Increased Permeability to Potassium
Hyperpolarisation
Depolarisation
Acetylcholine is the neurotransmitter
Noradrenaline is the neurotransmitter
The neurotransmitter binds to Beta 1 Receptors.

Explanation

Question 10 of 34

1

Which of the following are TRUE regarding conduction velocity

Select one or more of the following:

Is the same across the heart
Smaller fibres conduct faster than larger fibres
Larger fibres conduct faster than smaller fibres

Explanation

Question 11 of 34

2

Which of the following are functions of the cardiac skeleton

Select one or more of the following:

It is always fortified by cartilage and bone
Provides electrical discontinuity between atria and ventricles
Provides support for the AV Valves
Provides support for the Pulmonic and Aortic Valves
Provides an attachment site for ventricular muscles
Provides an attachment site for atrial muscles
Assists in Ventricular Contraction

Explanation

Question 12 of 34

1

Pacemaker Tissue is located in the

Select one of the following:

Epicardium
Myocardium
Endocardium
Pericardium

Explanation

Question 13 of 34

1

Adipose tissue can be found in the

Select one of the following:

Endocardium
Epicardium
Myocardium
Pericardium

Explanation

Question 14 of 34

5

Fill the blank space to complete the text.

Order the following events correctly

Your answer should be of the form ABCDE
Options:
A Activation of Ryanodine receptor channels in the Sarcoplasmic reticulum
B Opening of Voltage Gated Sodium Channels
C Tropomyosin shifts out of the actin cleft
D Influx of Calcium from the Sarcoplasmic Reticulum
E Calcium Binds to Troponin
F Crossbridge Cycle Occurs and Tension of Myocyte Increases
G Membrane Potential restored by the Na+/K+ ATPase and the Na+/Ca2+ Exchanger
H Depolarisation of Myocyte Above Threshold, Action Potential Initiated
I Influx of Calcium from the ECF
J Actin may now bind to Myosin
K Voltage Gated Calcium Channels Close
L Opening of Voltage Gated Calcium Channels
M Ca2+ ATPase activated, Calcium pumped back into the Sarcoplasmic Reticulum

Explanation

Question 15 of 34

2

Which of the following statements regarding an Isotonic Contraction are true?

Select one or more of the following:

Muscles fibres shorten but not force is developed
There is nothing to develop force against
Muscle Shortens with Maximal Velocity
Force generated at a Specific Length
Force generated at this length if a measure of the maximum ability to produce tension
Muscle shortens slowly
Muscle shortens with Maximal Force

Explanation

Question 16 of 34

3

Which of the following are likely to increase Afterload for the Left Ventricle

Select one or more of the following:

Increased sympathetic innervation
Hypovolaemic Shock
Systemic Hypertension
Pulmonary Hypertension
Increased Parasympathetic Innervation
Stenotic Aortic Valve
Incompetent Aortic Valve
Stenotic Pulmonary Valve
Incompetent Pulmonary Valve
Impaired Venous Return

Explanation

Question 17 of 34

3

Preload is synonymous with

Select one or more of the following:

ESV
EDV
CO
Venous Return
SV
HR
Systolic Blood Pressure
Diastolic Blood Pressure
TPR

Explanation

Question 18 of 34

1

On Trace 1 Person A has leads attached to the upper arms and thighs. On Trace 2 Person A has leads attached to the forearms and lower legs.

If all other variables are constant, following Einthoven's Hypothesis, the ECG for Trace 1 and 2 would be identical.

Select one of the following:

True
False

Explanation

Question 19 of 34

1

The Magnitude of the Dipole on a ECG is determined by

Select one or more of the following:

How many cells are depolarising
Heart Rate
Vector Analysis of Simultaneous Dipoles
None of the above

Explanation

Question 20 of 34

1

A Dog has the positive lead on his left arm, and the negative lead on his right arm, and the ground lead attached to the right leg. This arrangement is described as:

Select one of the following:

Lead 1
Lead 2
Lead 3
None of the Above

Explanation

Question 21 of 34

1

Which lead is considered most useful

Select one of the following:

Lead 1
Lead 2
Lead 3
All Leads are equally useful

Explanation

Question 22 of 34

1

Atrial depolarisation occurs during the

Select one of the following:

P Wave
QRS Complex
T Wave
None of the Above

Explanation

Question 23 of 34

1

The T Wave is highly variable in domestic animals, it could be positive or negative deflection, or sometimes not even noticeable.

Select one of the following:

True
False

Explanation

Question 24 of 34

2

A Patient presents with a prolonged P-R Interval on their ECG. All other intervals are within normal range. This could suggest

Select one or more of the following:

A Delay between Atrial Depolarisation and Ventricular Depolarisation
A Blockage at the AV Node
Left Sided Congestive Heart Failure
Sinus Tachycardia
Sinus Bradycardia

Explanation

Question 25 of 34

1

Exercise, Anxiety and Fever would most likely cause

Select one of the following:

Sinus Tachycardia
Sinus Bradycardia
Sinus Arrythmias
None of the above

Explanation

Question 26 of 34

1

A Patient presents with an absence of P waves on their ECG. The QRS and T Waves are normal.

The Patient most likely has a

Select one of the following:

SA Block
1st Degree AV Block
2nd Degree AV Block
3rd Degree AV Block
None of the Above

Explanation

Question 27 of 34

2

A Patient has a 3rd Degree AV Block. Which of the following features would you expect to be present on their ECG.

Select one or more of the following:

P wave and QRS/T Waves are Independent
P wave and QRS/T Waves are dependent, but have an abnormally long conduction time between them
There isn't 1 QRS complex for every P Wave
Ventricular Rate is Slow
Atrial Contraction is Slower than normal

Explanation

Question 28 of 34

2

A Patient's ECG shows QRS Complexes that are not always preceded by a clear P Wave. Which of the following are possible

Select one or more of the following:

VPC's
Paroxysmal Tachycardia
Atrial Fibrilation
Ventricular Fibrilation
AV Block
SA Block

Explanation

Question 29 of 34

1

Atrial Contraction contributes what percentage to ventricular filling?

Select one of the following:

0%
20%
40%
60%
80%
100%
50%

Explanation

Question 30 of 34

1

With an Increase in Heart Rate, Atrial Contribution to Ventricular filling also increases

Select one of the following:

True
False

Explanation

Question 31 of 34

3

During the 1st Phase of Ventricular Systole which of the following statements are true?

Select one or more of the following:

The contraction is Isometric
Ejection is Rapid
Mitral Valve is Closed
Tricuspid Valve is Closed
Aortic Valve is Closed
Pulmonary Valve is Closed
Atrial Pressure wave, c wave, occurs in the venous system
Pressure within the ventricle increases
Pressure within the ventricle decreases
Aortic Pressure Rises

Explanation

Question 32 of 34

1

Which of the statements regarding the Dichrotic Notch are incorrect

Select one of the following:

It occurs at the conclusion of Ventricular Systole
It is a result of blood flowing back into the leaves of Aortic Valve after it closes
Results in a sharp decrease in Aortic Pressure
Would be less noticeable in animal with an incompetent Aortic Valve
All the above are correct

Explanation

Question 33 of 34

1

Which of the following are incorrect

Select one of the following:

Cardiac Output is proportional to Stroke Volume
An Increase in Heart Rate would result in a corresponding increase in Stroke Volume
EDV and Venous Return are synonymous
Ejection Fraction = SV/EDV
A decrease in Preload will decrease Cardiac Output

Explanation

Question 34 of 34

1

The 4th Heart Sound is caused by the vibration of ventricular wall due to deceleration of blood leaving the ventricles

Select one of the following:

True
False

	Created by Daniel Mosele over 9 years ago

Veterinary Bioscience 1: Cardiovascular System (Anatomy and Physiology Lectures) Quiz on Lectures 3-6 Cardiac Physiology, created by Daniel Mosele on 28/08/2016.

Lectures 3-6 Cardiac Physiology

Question 1 of 34

Which of the following statements are TRUE regarding cardiac myocytes?

Select one of the following:

Explanation

Question 2 of 34

Select from the dropdown lists to complete the text.

The Na+/K+ ATPase helps maintain the resting membrane potential of roughly -85mV in cardiac myocytes. For each unit of ATP expended 3 2 1( 3, 2, 1 ) Na+ K+( Na+, K+ ) Ions are pumped out and 2 1 3( 2, 1, 3 ) K+ Na+( K+, Na+ ) ions pumped in

Explanation

Question 3 of 34

During Diastole which of the following movement of ions are occurring in cardiac myocytes.

Select one or more of the following:

Explanation

Question 4 of 34

Which of the following statements are correct?

Select one or more of the following:

Explanation

Question 5 of 34

Which of the following statements is FALSE regarding the refractory period of a cardiac myocyte Action Potential?

Select one of the following:

Explanation

Question 6 of 34

Fast response action potentials occur in the SA Node

Select one of the following:

Explanation

Question 7 of 34

Fill the blank spaces to complete the text.

Order the following from those most permeable to sodium and calcium, to those least permeable to sodium and calcium. 1. 2. 3. 4. Options: Bundle of His SA Node Purkinje Fibres AV Node

Explanation

Question 8 of 34

Which of the following are true of pacemaker cells in the AV Node

Select one or more of the following:

Explanation

Question 9 of 34

Parasympathetic/Vagal Innervation of the SA Node will result in

Select one or more of the following:

Explanation

Question 10 of 34

Which of the following are TRUE regarding conduction velocity

Select one or more of the following:

Explanation

Question 11 of 34

Which of the following are functions of the cardiac skeleton

Select one or more of the following:

Explanation

Question 12 of 34

Pacemaker Tissue is located in the

Select one of the following:

Explanation

Question 13 of 34

Adipose tissue can be found in the

Select one of the following:

Explanation

Question 14 of 34

Fill the blank space to complete the text.

Explanation

Question 15 of 34

Which of the following statements regarding an Isotonic Contraction are true?

Select one or more of the following:

Explanation

Question 16 of 34

Which of the following are likely to increase Afterload for the Left Ventricle

Select one or more of the following:

Explanation

Question 17 of 34

Preload is synonymous with

Select one or more of the following:

Explanation

Question 18 of 34

On Trace 1 Person A has leads attached to the upper arms and thighs. On Trace 2 Person A has leads attached to the forearms and lower legs. If all other variables are constant, following Einthoven's Hypothesis, the ECG for Trace 1 and 2 would be identical.

Select one of the following:

Explanation

Question 19 of 34

The Magnitude of the Dipole on a ECG is determined by

Select one or more of the following:

Explanation

Question 20 of 34

A Dog has the positive lead on his left arm, and the negative lead on his right arm, and the ground lead attached to the right leg. This arrangement is described as:

Select one of the following:

The Na+/K+ ATPase helps maintain the resting membrane potential of roughly -85mV in cardiac myocytes.

For each unit of ATP expended ( 3, 2, 1 ) ( Na+, K+ ) Ions are pumped out and ( 2, 1, 3 ) ( K+, Na+ ) ions pumped in

Order the following from those most permeable to sodium and calcium, to those least permeable to sodium and calcium.

1.
2.
3.
4.

Options:
Bundle of His
SA Node
Purkinje Fibres
AV Node

On Trace 1 Person A has leads attached to the upper arms and thighs. On Trace 2 Person A has leads attached to the forearms and lower legs.

If all other variables are constant, following Einthoven's Hypothesis, the ECG for Trace 1 and 2 would be identical.

A Patient presents with an absence of P waves on their ECG. The QRS and T Waves are normal.

The Patient most likely has a